Locking device for trailer hitches and method therefor

ABSTRACT

A method and apparatus to secure the coupler section of a trailer provides a locking device that includes a lock housing having a hitch ball element to engage the recess in the coupler, a shackle member lockable to the housing and having a bridge section that spans the hitch ball element and, and a latch assembly to latch and unlatch the shackle member. The shackle member is shown to be U-shaped with legs that extend through and secure to the lock housing. The latch assembly provides a ratchet-type engagement to allow adjustable locking. A rotatable lock mechanism drives a cam based latch mechanism between a latch state and an unlatch state.

FIELD OF THE INVENTION

The present invention broadly concerns locking devices operative toprevent unauthorized access, theft or unauthorized use of objects. Moreparticularly, however, the present invention is directed to a lockingdevice to prevent the theft or unauthorized use of a trailer. Thepresent invention specifically concerns a locking device which mateswith the hitch recess in a trailer coupler so as to preclude access tothat hitch and to secure the trailer to a stationary, relativelyimmoveable object.

BACKGROUND OF THE INVENTION

The use of towable vehicles has become increasingly popular for bothutilitarian and pleasure purposes. A wide variety of both tractor andtrailer vehicles are employed for general or special purposes. Tractorvehicles, for example, include both those that travel on road, such ascars, sport utility vehicles, trucks, semi-tractors and a wide varietyof farm and agricultural tractor equipment. Trailer vehicles, on theother hand, include utility trailers, commercial trailers, recreationalvehicle trailers, boat trailers, camping trailers, to name a few.

One of the most common structures used to link a tractor vehicle to atrailer vehicle is the hitch ball and trailer coupler. Here, a mountingstructure is provided on the tractor vehicle, and the mounting structuresupports a generally spherical hitch ball in an upright manner. Thetrailer vehicle then includes a tongue associated with the frame of thetrailer vehicle with this tongue having a forwardly extending hitch ballcoupler that includes a recess that mateably receives the hitch ball andthat can be secured thereto during the towing operation. During thetowing operation, the hitch ball and the trailer hitch coupler arelatched together to prevent inadvertent disengagement. In addition, itis known to provide the latch mechanisms of the trailer hitch couplerwith a locking device so that the trailer can be locked onto the hitchball.

However, when a trailer vehicle is disconnected from the towing vehicle,it may become the target of unauthorized use or theft. In such cases, athief or other user may merely attach another towing vehicle to thetrailer hitch coupler and drives away with the trailer vehicle. In orderto deter theft, it is known to lock the trailer hitch coupler latch inan unlatched condition so that it may not be secured in a normal mannerto another tractor vehicle. However, the recess of the trailer hitchcoupler is still available for mating with a hitch ball of a thief'stractor vehicle.

Accordingly, it is also known to provide a locking structure thatengages the hitch ball recess of a trailer hitch coupler and locks ontothe trailer hitch coupler so that the locking device interferes with theability to attach a tractor vehicle. For example, U.S. Pat. No.5,433,468 issued Jul. 8, 1995 to Dickson discloses a theft resistantdevice wherein a cylindrical member may be inserted into the recess of atrailer hitch coupler. A pair of arms are pivotally secured to thiscylindrical member, on either side thereof, so that they may pivotacross the top of the trailer hitch coupler and be secured by a lockshackle that may pass through openings in the free ends of the arms.This device, however, can be subject to attack by a thief and removedsimply by hammering the arms out of alignment or breaking the arms offof the device so that the cylinder, and thus the locking device, may beremoved from the trailer hitch coupler.

In U.S. Pat. No. 4,141,569, issued Feb. 27, 1979 to Dilk, another theftprevention device for use on a detached trailer vehicle is disclosed.Here, a hitch ball structure is mounted in a box-like housing that has ahinged lid. The hitch ball structure is positioned in the recess of atrailer hitch coupler, and the lid is then pivoted into place so as totrap the hitch coupler between the hitch ball structure and a downwardlydepending post that is mounted to the lid. The lid may then be padlockedinto a closed position. U.S. Pat. No. 4,032,171, issued Jun. 28, 1977 toAllen et al., teaches a somewhat similar technique of locking a trailerhitch coupler. Each of these devices are relatively bulky and complexand again are subject to attack by a thief due to the exposed parts.

U.S. Pat. No. 3,884,055, issued May 20, 1975 to Vuillemot also locksinto the recess of a trailer hitch coupler. Here, a cylindrical post ismounted to a U-shaped bracket with the post sized to be received in therecess. The legs of the bracket are provided with openings through whicha bar that extends across the trailer hitch coupler and the post withthis bar being locked in the bracket by means of a padlock. While thisdevice is rather compact, it still exposes the locking structure toattack by a thief.

While the above-referenced devices do, in fact, lock onto a trailerhitch coupler, they suffer other disadvantages in addition to thosenoted above. For example, none of the devices disclosed in theabove-referenced patents are readily adjustable for differentlydimensioned trailer hitch couplers moreover, each relies on anindependent padlock which can inadvertently be misplaced so that thelocking structure becomes less useable until another padlock isobtained.

Accordingly, there remains a need for improved locks which may lock ontoa trailer hitch coupler in order to discourage theft of a trailervehicle when it is detached from a towing vehicle. There is a need for adevice which is both compact, strong and durable such that the deviceresists attack by a would-be thief. There is further a need for such alocking device that has a locking mechanism incorporated therein so asto avoid the requirement of an auxiliary padlock.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a new and usefullocking device and method to secure to a coupler section of the trailer.

Another object of the present invention is to provide a locking devicefor a trailer hitch coupler that is robust in construction.

It is another object of the present invention to provide a lockingdevice for a trailer hitch coupler that is adjustable to accommodatedifferent sizes and configuration of such trailer hitch couplers.

A further object of the present invention is to provide a locking devicefor a trailer hitch coupler that is configured so as to resist physicalattack sufficient to remove the device from the trailer hitch coupler towhich it is secured.

Still a further object of the present invention is to provide a lockingdevice for a trailer hitch coupler which has a locking mechanismintegrally associated therewith.

According to the present invention, then, a locking device is adapted tosecure to a coupler section of a trailer wherein the coupler section hasa hitch ball recess. Broadly, the locking device includes a lock housingthat has a hitch ball element supported thereby that is sized andadapted to be engaged with and disengaged from the hitch ball recess ofa coupler section of a trailer. A shackle member is releaseablysecurable to the lock housing to define a retained state. The shacklemember includes a bridge section that extends across the hitch ball whenin the retained state whereby the coupler section becomes non removablytrapped between the hitch ball element and the bridge section when inthe retained state. The shackle member is releasable from the lockhousing to define a release state wherein the coupler section can bereleased from the hitch ball element. A selectively lockable latchassembly is disposed in the lock housing and is operative to movebetween latched state wherein the shackle member is latched in theretained state and an unlatched state when shackle member may be movedto the released state.

While the shackle member may include a single leg section supporting thebridge section, the exemplary embodiment discloses a shackle member thatis generally U-shaped in configuration including a pair of spaced apartleg sections and a bridge section extending therebetween. In any event,either the single leg section or the pair of legs sections are securableto the lock housing when in the retained state with the bridge sectionbeing oriented across the hitch ball element. Moreover, a latchstructure is located on each leg section, and the lock housing includesone or more passageways formed therein which are sized to receive arespective leg section when in the retained state. The latch assembly isoperative to engage the latch structure on the leg section when in thelatch state to prevent removal of the leg section from the lock housing.The latch structure may be defined by a plurality of first latch teeth,and the latch mechanism includes a latch block having at least one latchtooth, but in the exemplary embodiment, a plurality of latched teeth aredisclosed, that are operative to engage the first latch teeth when inthe retained state. The latch block is biased toward the retained stateso as to define a ratchet engagement whereby the leg section(s) may beinserted into but not removed from the lock housing when the latchmechanism is in the latched state.

In the exemplary embodiment, the latch assembly includes a latchmechanism and a lock mechanism that are mechanically linked to oneanother. The lock mechanism is rotatable between first and secondrotational positions thereby to move the latch mechanism between thelatched and unlatched states and includes a cam post. A limit stopstructure is provided to control the magnitude of rotation. Here, thelatch mechanism may include a latch rod having a cam surface associatedtherewith and moveable between first and second rod positions thatrespectively correspond to the latched and unlatched states. The lockmechanism then includes a cam element that interacts with the camsurface so that rotation of the lock mechanism between the first andsecond rotational positions acts to cause movement of the latch rodbetween the first and second rod position. In the exemplary embodiment,two such latch rods are provided, and each latch rod includes a shaftportion and a head portion located at a first end. The head portion hasa lop-sided opening that forms the cam surface. A latch block is thenlocated at the second end of the shaft portion opposite the first end.The head portion has the cam surface formed therein and a spring ispositioned along the shaft portion to bias each of the latch rodstowards the first rod position.

Again, in the exemplary embodiment, the lock housing includes a bodyportion that has a longitudinal throughway extending therethrough and atransverse bore intersecting the throughway. The hitch ball is orientedgenerally orthogonally to the throughway and to the bore. An elongatedtubular casing is disposed in the throughway. The latch mechanism isthen disposed in the casing and the lock mechanism is disposed in thebore. The casing includes at least one exposed portion that projectsexteriorly of the body portion and as a passageway formed therein sizedto received the leg section when in the retained state. The latchassembly then operated to engage the latch structure to prevent removalof the leg section from the casing. Where the shackle member has two legsections, the casing includes oppositely projecting exposed portionseach with a passageway formed therein.

The present invention is also directed to a method of securing thecoupler section of the trailer that has a hitch ball recess. Here, thebroad method includes the step of engaging a hitch ball recess with ahitch ball element. Next, a portion of the coupler section adjacent tothe hitch ball element is fanned with a first portion of the shacklemember in such manner that a portion of the coupler members positionbetween the first portion of the shackle member and the hitch ballelement. The first portion of the shackle member is then adjusted totrap the portion of the coupler member in a nonremoveable manner betweenthe hitch ball element and the first portion of the shackle member todefine the locked state. The second portion of the shackle member isthen lockably retained relative to the hitch ball element such that thefirst portion of the shackle member is locked in the lock state. Thebroad method may also include the step of selectively releasing thesecond portion of the shackle member such that the first portion of theshackle member is unlocked and removeable thereby permittingdisengagement with the portion of the coupler section. The step ofadjusting the first portion of the shackle member may be accomplished bya ratchet mechanism. Other method steps contemplated by the abovedescribed structure are contemplated within this method.

These and other objects of the present invention will become morereadily appreciated and understood from a consideration of the followingdetailed description of the exemplary embodiments of the presentinvention when taken together with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view in elevation showing the locking device accordingto the present invention secured to the coupler section of a trailer ina retained state;

FIG. 2 is a perspective view of the locking device shown in FIG. 1;

FIG. 3 is an exploded view in perspective of the locking device shown inFIG. 2;

FIG. 4 is an exploded view in perspective showing a portion of the latchmechanism of the locking device according to the exemplary embodiment ofthe present invention;

FIG. 5 is a side view in cross-section showing the body portion of thelock housing illustrated in FIG. 4;

FIG. 6 is a top plan view showing the lock core of FIG. 4;

FIG. 7 is a front view in elevation showing the lock core of FIG. 6;

FIG. 8 is a cross-sectional view taken about lines 8-8 of FIG. 7;

FIG. 9 is a cross-sectional view taken about lines 9-9 of FIG. 7;

FIG. 10 is a top plan view of the tubular casing used with the lockmechanism illustrated in FIG. 4;

FIG. 11 is a front view in elevation showing the tubular casing of FIG.10;

FIG. 12 is a cross-sectional view taken about lines 12-12 of FIG. 11;

FIG. 13 is a perspective view showing the latch rod and block structureof the latch mechanism according to the present invention;

FIG. 14 is a front view in elevation of a latch rod shown in FIG. 13;

FIG. 15 is a front view in elevation of a latch lock illustrated in FIG.13;

FIG. 16 is top plan view of the latch block shown in FIG. 15;

FIG. 17 is a perspective view of a rod cam and lock member of the lockmechanism of the present invention;

FIG. 18 is a front view in cross-section showing the locking device ofthe present invention with the shackle member in a retained state thatthe latch assembly in a latch state with this view not showing thehousing cover members; and

FIG. 19 is a front view in cross-section, similar to FIG. 18, butshowing the latch assembly in an unlatch state so that the shacklemember may be moved from the retained state to the released state.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The present invention broadly concerns locks and locking devices adaptedto secure an object. The present invention is particularly concernedwith a locking device that is adapted to secure to the coupler sectionof a trailer that has a hitch ball recess so as to prevent attachment ofthe trailer hitch coupler to a towing vehicle when the locking device issecured thereto. This locking device also permits the securing of thecoupler section of the trailer to a stationary object to preventunauthorized use or theft of the trailer.

With reference now to FIG. 1, locking device 10 is introduced and isshown secured to a coupler section 12 of a trailer (not shown). Couplersection 12 typically forms part of the tongue of a trailer (not shown)and includes a recess 14 (shown in phantom) which is adapted to receivethe hitch ball of a towing vehicle. An engagement mechanism 15, as isknown, is provided to engage a hitch ball during use but can release toallow removal of the hitch ball. Also illustrated in FIG. 1 is a chain16 having a plurality of links 18 which secure to locking device 10 sothat locking device 10 can be secured to an object (again not shown) toprevent an unauthorized removal or theft of the trailer to which couplersection 12 is affixed.

Locking device 10 is better illustrated in FIG. 2 where it can be seenthat locking device 10 includes a generally U-shaped shackle member 20that has a pair of parallel leg sections 22 and a bridge section 24 thatextends between leg sections 22. In FIG. 2, shackle member 20 is shownin a retained state where it is secured to a lock housing 30, thestructure of which is described in greater detail below. Lock housing 30includes a hitch ball element 32 supported thereby with hitch ballelement 32 being sized and adapted to be engaged with and disengagedfrom the hitch ball recess 14 of coupler section 12 of the trailer. Asused herein,“hitch ball element” means any shaped structure that issized and adapted to be received and engaged in the hitch ball recess ofthe coupler section 12.

With reference to both FIGS. 1 and 2, it may be seen that bridge section24, when in the retained state, extends across hitch ball element 32 sothat coupler section 12 will become nonremoveably trapped between hitchball element 32 and bridge section 24. A selectably lockable latchassembly is disposed in lock housing 30 and is operative to move betweena latch state wherein the shackle member 20 may be latched in theretained state and an unlatched state wherein the shackle member 20 maybe moved to a released state. A lock mechanism 34 is also disposed inlock housing 30 in order to operate the latch mechanism. Access to lockmechanism 34 is protected by means of a sliding door 36 that can slidein the direction of arrow (A) so that it may move from an open position(FIG. 2) to a closed position (FIG. 1).

With reference now to FIG. 3, it may be seen that lock housing 30includes a body portion 38 that mounts a tubular casing 40 extendinglongitudinally therethrough with tubular casing 40 including oppositelyprojecting casing sections 42 located exteriorly of body portion 38.Body portion 38 rigidly mounts hitch ball element 32 and, in thisembodiment, hitch ball element 32 and body portion 38 are integrallycast with one another. Hitch ball element 32 is shown with a verticalbore 44 that is adapted to receive a plug 46. However, it should beunderstood that hitch ball element 32 could be formed as a solid pieceof material and it may take other shapes other than the generallyspherical shape shown in FIG. 3. Body portion 38 also includes a bore48, and, it should be understood that, in this embodiment, bore 48 hitchball element 32 and casing 40 are all generally orthogonal, i.e.perpendicular, to one another. Bore 48 includes the lock mechanism 34which is shown to include a rod cam 50 and a lock member 52 that, whenassembled, are secured in bore 48 by means of a retaining pin 54. Bodyportion 38 should be formed of any suitable high strength material suchas steel.

As shown still in FIG. 3, leg sections 22 of shackle member 20 arespaced apart and sized to extend through a pair of passageways 56 formedin casing sections 42 and secured therein by the latch assembly whichwill engage latch structures in the form of a plurality of latch teeth58 formed on each leg section 22. A pair of cooperating housing covermembers 60 and 62 are formed so as to nestably receive lock housing 30and mount access door 36 therein, as is shown in FIGS. 2 and 3. Coversections 60 and 62 are smoothly contoured and present a reduced profilewhen locking device 10 is secured to coupler section 12 so as toincrease the integrity of locking device 10 against hammer blows and thelike should an unauthorized person seek to remove locking device 10 fromcoupling section 12.

With reference next to FIGS. 4 and 5, it may be seen that body portion38 has a longitudinal throughway 64 extending therethrough which issized for close-fitted, mated engagement with tubular casing 40. Casing40 may be fastened in body portion 38, for example, by retaining pins66. Tubular casing 40 is in the form of a hollow tubular memberconstructed, for example, of case hardened steel. Casing 40 includes acentral opening 68 that is formed at an axis that is perpendicular topassageways 56 to allow interaction of lock mechanism 34 with the latchmechanism, as described below. A latch core 70 is sized for close fittedtelescopic mating with casing 40 and includes a configured chamber 72which receives the latching structure as described below.

The structure of latch core 70 is best shown in FIGS. 6-9 where it maybe seen that latch core 70 is molded, for example, out of a durableplastic material. Latch core 70 is symmetric about a plane perpendicularto its longitude so that a pair of chambers 74 are located in latch core70 and are interconnected by a slotted opening 76. Each of chambers 74include a bore 78 extending thereto with bore 78 sized and adapted toreceive leg sections 22 of shackle member 20. Each of chambers 74includes a spring chamber section 80 and a latch block chamber section82. A transverse bore 72 is formed centrally of latch core 70 and has apilot recess 84 formed coaxially therewith. With reference to FIGS. 8and 9, it may be seen that bores 78, spring chamber sections 80 andlatch block chamber sections 82 extend diametrically through latch core80 while slotted opening 76 extends the majority of the diametricdistance of latch core 70 but not entirely therethrough. One end oflatch core 80 is provided with a small tab 85 that extends radiallytherefrom.

The structure of tubular casing 40 is best shown in FIGS. 10-12. Here,as noted above, tubular casing 40 has a longitudinally extendinginterior 86, a central opening 68 and a pair of passageways 56, witheach passageway 56 being defined by a pair of opposed openings 57.Openings 57, and thus passageways 56, are sized to receive leg sections22 of shackle member 20. When latch core 70 is mated with tubular casing40, bores 78 respectively axially register with passageways 56.Similarly, central opening 68 of casing 40 registers with bore 72 oflatch core 70. To facilitate this registration, each end of casing 40has a small slot 87 formed therein. Tab 85 of latch core 70 will matewith either of these slots 87 to ensure proper registration of the twopieces. By providing a slot 87 at each end of casing 40, latch core 70may be slid into the interior from either end due to its symmetry.

With reference now to FIG. 13, it may be seen that the latchingcomponents of latch mechanism 88 are depicted, with the components oflatch mechanism 88 being illustrated in greater detail in FIGS. 14-16.In these figures, it may be seen that latch mechanism 88 includes a pairof latch rods 90 each of which having a shaft portion 92 and a headportion 94 located at a first end of the shaft portion. A latch block 96is supported at a second end of shaft portion 92. When assembled, a coilspring 98 extends around each shaft portion 92. Latch box 96 are mountedonto latch rod 90 by means of pins 100 shown in FIG. 13.

With reference to FIGS. 6-9 and 13, it should now be understood thatlatch mechanism 88 is sized and configured for nested insertion intochambers 74 and slotted opening 76 of latch core 70. To this end, whenassembled, head portions 94 of latch rods 90 reside in slotted portion76 with coil springs 98 residing in spring chamber sections 80. Latchblocks 96 are configured for slideable receipt in latch block chambersections 82 and can move between a first position rod partially in theregion defined by bores 78 to a second rod position wherein latch blocks96 are out of sections 82.

As is shown in FIG. 14, head portion 94 of each latch rod 90 includes acam surface 102 formed by a lopsided opening 104, the operation of whichis described in greater detail below. Turning now to FIGS. 15 and 16, itmay be seen that each latch block 96 includes a pair of parallel wings106 having openings to receive a fastening pin 100 when the second endportion of latch rod 90 is mated therewith. More importantly, latchblock 96 includes second latch structures in the form of a plurality ofsecond latch teeth 108 which are sized for cooperative engagement withlatch teeth 58 on each leg section 22.

The purpose and function of cam surface 102 can be more freelyappreciated with reference to FIGS. 3 and 17 which show lock mechanism34 in greater detail. As is shown in these figures, lock mechanism 34includes a lock member 52 of a type known in the art which receives atubular key. Lock member 52 has an outer casing 110 that receives arotatable lock core 112 therein. Thus, lock core 112 may rotate relativeto casing 110 when a proper key is inserted and turned. Post 116 isconfigured to mate with an axial cavity 118 in rod cam 50. Casing 110also has a nub 120 extending longitudinally therefrom, and rod cam 50includes an arcuate channel 114 formed approximately 90 degrees of thecircumference thereof. Nub 120 is configured to reside in channel 114.Thus, when rod cam 50 and lock member 52 are mounted in body portion 38,rotation of lock core 112 will rotate rod cam 50. However, this rotationis limited to approximately 90 degrees of rotation due to the limitstops provided by channel 114 and nub 120. Rod cam 50 has a camstructure 122 and an axial pilot post 124 at an end thereof oppositecavity 118 and nub 120. When assembled, pilot post 124 engages pilotrecess 84 with cam 122 engaging each opening 104 of the respective latchrods 90.

The assembly and operation of locking device 10 may now be more fullyunderstood with reference to FIGS. 18 and 19. In FIG. 18, shackle member20 is shown secured to the lock housing to define a retained state. Inthis position, cam 122 has a longer dimension, or width, that extendsvertically that is greater than its horizontal thickness (as shown inFIG. 17) so that latch rods 90 may be biased outwardly to the first rodposition by means of springs 98 acting against latch blocks 96.Accordingly, latch blocks 96 are biased and are shown in the latchstate. In this state, the latch teeth 108 on each latch block 96selectively engage selected ones of latch teeth 58 to retain shacklemember in the retained state. Due to the biasing of latch blocks 96against the restoring force of springs 98, it should be understood thatthe latch mechanism defines a ratchet engagement so that, even when thelatch mechanism is in the latch state, leg sections 22 of shackle member20 may be inserted therein and engage latch blocks 96 in a ratchet likemanner permitting adjustment of shackle member 20 so that bridge section24 may trap coupler section 12 between hitch ball element 32 and bridgesection 24.

FIG. 19 shows the locking device 10 wherein the latch assembly is movedto the unlatch state so that shackle member 20 may moved from the retainstate to the release state. Here, it may be seen that cam member 122 hasbeen rotated 90 degrees so that it acts against cam surfaces 102 ofopenings 104 and draws latch rods 90 toward one another against theforce of springs 98. This occurs when a key is inserted into lock member52 and lock core 112 is rotated with respect to casing 110. When latchrods 90 are drawn towards one another, latch blocks 96 are drawn towardone another to disengage latch teeth 108 from latch teeth 58. In thisposition, of course, shackle member 20 may now be withdrawn or removedfrom lock housing 30 and released therefrom.

From the foregoing, it should be appreciated that the locking device 10is assembled by affixing tubular casing 40 in body portion 38 by meansof pins 66. Latch mechanism 88 that includes a pair of latch rods, apair of latch blocks and a pair of springs 98 are then mounted inchambers 74 and slotted opening 76 with openings 104 registering withbore 72. Lock core 70 with latch mechanism 88 mounted therein is theninserted into casing 42 that extends throughway 64. Lock mechanism 34may then be inserted into bore 48 by first inserting rod cam 50 so thatcam 122 resides in openings 104 with pilot post in pilot recess 84. Lockmember 50 is then inserted so that post 116 engages cavity 118 and thelock core is pinned into position by means of retaining pin 54. Coversections 62 are then mounted over the lock housing and secured theretoin any convenient manner. At this time, door 36 is also placed intoposition to slide so as to selectively conceal or reveal lock mechanism34.

From the foregoing, it may also be appreciated that the presentinvention contemplates a method that may be accomplished by the stepsinherent in the described structure. Generally, this method includesengaging a hitch ball recess of a coupler section of the trailer bymeans of a hitch ball element. The method includes the stop of spanninga portion of the coupler section adjacent to the hitch ball element witha shackle member in a manner such that a first portion of the couplermember is located between the shackle member and the hitch ball elementand then adjusting the shackle member relative to the hitch ball elementso as to nonremoveably trap the first portion of the coupler memberbetween the hitch ball element and the shackle member to define a lockedstate. The method then includes lockably retaining a second portion ofthe shackle member relative to the hitch ball element so that the firstportion of the shackle member is locked in the lock state. This methodmay also include the step of selectively releasing the second portion ofthe shackle member so that the first portion of the shackle member isunlocked and removable, thereby permitting disengagement of the firstportion of the coupler section. The method can also accomplish the stepof adjusting by means of a ratcheting action wherein a latch mechanismis resiliently biased into ratcheting engagement with a second portionof the shackle member.

Accordingly, the present invention has been described with some degreeof particularity directed to the exemplary embodiment of the presentinvention. It should be appreciated, though, that the present inventionis defined by the following claims construed in light of the prior artso that modifications or changes may be made to the exemplary embodimentof the present invention without departing from the inventive conceptscontained herein.

1. A locking device adapted to secure to a coupler section of a trailerthat has a hitch ball recess, comprising: (A) a lock housing including ahitch ball element supported thereby that is sized and adapted to beengaged with and disengaged from the hitch ball recess of a couplersection of a trailer; (B) a shackle member releasably securable to saidlock housing to define a retain state, said shackle member including abridge section that extends across said hitch ball element when in theretain state whereby said coupler section becomes non-removably trappedbetween said hitch ball element and said bridge section when in theretain state, said shackle member releasable from said lock housing todefine a release state wherein said coupler section can be released fromsaid hitch ball element; and (C) a selectively lockable latch assemblydisposed in and integral with said lock housing and operative to movebetween a latch state wherein said shackle member is latched in theretain state and an unlatch state wherein said shackle member may bemoved to the release state.
 2. A locking device according to claim 1wherein said shackle member is generally U-shaped in configurationincluding a pair of spaced apart leg sections and a bridge sectionextending therebetween, each of said leg sections securable to said lockhousing when in the retain state with said bridge section orientedacross said hitch ball element.
 3. A locking device according to claim 1wherein said shackle member includes at least one leg section supportingsaid bridge section and having a latch structure thereon and whereinsaid lock housing includes at least one passageway therein sized toreceive said leg section when in the retain state, said latch assemblyoperative to engage said latch structure when in the latch state toprevent removal of said leg section from said lock housing.
 4. A lockingdevice according to claim 3 wherein said latch structure is defined by aplurality of first latch teeth, said latch assembly including a latchblock having at least one second latch tooth operative to engage aselected one of said first latch teeth when in the retain state.
 5. Alocking device according to claim 4 wherein said latch block is biasedtoward the latch state.
 6. A locking device according to claim 5 whereinsaid first latch teeth and said second latch tooth define a ratchetengagement whereby said leg section may be inserted into but not removedfrom said locking housing when said latch mechanism is in the latchstate.
 7. A locking device according to claim 4 including a plurality ofsecond latch teeth on said latch block, said second latch teethoperative to engage selected ones of said first latch teeth when in theretain state.
 8. A locking device according to claim 1 wherein saidlatch assembly includes a latch mechanism and a lock mechanismmechanically linked to one another, said lock mechanism rotatablebetween first and second rotational positions thereby to move said latchmechanism between the latch and unlatch states.
 9. A locking deviceaccording to claim 8 wherein said latch mechanism includes a latch rodhaving a cam surface associated therewith and movable between first andsecond rod positions that respectively correspond to the latch andunlatch states, said lock mechanism including a cam element thatinteracts with the cam surface such that rotation of said lock mechanismbetween the first and second rotational positions acts to cause movementof said latch rod between the first and second rod positions.
 10. Alocking device according to claim 9 wherein said latch rod includes ashaft portion and a head portion located at a first end of said shaftportion, said latch mechanism including a latch block located at asecond end of said shaft portion opposite the first end portion thereof,said head portion having the cam surface formed therein, and including aspring positioned along said shaft portion that is operative to biassaid latch rod toward the first position.
 11. A locking device accordingto claim 1 wherein said lock housing includes a body portion having alongitudinal throughway extending therethrough and a transverse boreintersecting the throughway with said hitch ball oriented generallyorthogonally to the throughway and to the bore, and including anelongated tubular casing disposed in the throughway.
 12. A lockingdevice adapted to secure to a coupler section of a trailer, comprising:(A) a lock housing including a hitch ball element supported thereby thatis sized and adapted to mate with a coupler section of a trailer, saidlock housing having a pair of spaced-apart passageways extendingtherethrough; (B) a shackle member releasably securable to said lockhousing to define a retain state, said shackle member including a pairof spaced-apart leg sections and a bridge section extendingtherebetween, said leg sections respectively configured to pass throughthe pair of passageways when in the retain state whereby said couplersection can be non-removably engaged between said hitch ball element andsaid bridge section, said shackle member releasable from said lockhousing to define a release state wherein said coupler section can beengaged by and released from said hitch ball element; (C) a latchmechanism disposed in said lock housing and operative to move between alatch state wherein said shackle member is latched in the retain stateand an unlatch state wherein said shackle member may be moved to therelease state; and (D) a lock mechanism that is integral with the lockhousing and that is movable between a lock state to lock said latchmechanism in the latch state such that said shackle member is in theretain state and an unlock state to unlock said latch mechanism so thatit may move to the unlatch state thereby allowing said shackle member tomove to the release state.
 13. A locking device according to claim 12wherein at least one of said leg sections has a latch structure thereon,said latch mechanism operative to engage said latch structure when inthe latch state to prevent removal of said leg sections from said lockhousing.
 14. A locking device according to claim 13 wherein said latchstructure is defined by a plurality of first latch teeth, said latchmechanism including at least one latch block having at least one secondlatch tooth operative to engage a selected one of said first latch teethwhen in the retain state.
 15. A locking device according to claim 14wherein said latch block is biased toward the latch state.
 16. A lockingdevice according to claim 15 wherein said first latch teeth and eachsaid second latch tooth define a ratchet engagement whereby said legsections may be inserted into but not removed from said locking housingwhen said latch mechanism is in the latch state.
 17. A locking deviceaccording to claim 16 including a plurality of second latch teeth onsaid latch block, said second latch teeth operative to engage selectedones of said first latch teeth when in the latch state.
 18. A lockingdevice according to claim 12 wherein each of said leg sections has alatch structure thereon, said latch mechanism operative to engage saidlatch structure when in the latch state to prevent removal of said legsections from said lock housing.
 19. A locking device according to claim12 wherein said lock mechanism is rotatable between first and secondrotational positions thereby to move said latch mechanism between thelatch and unlatch states.
 20. A locking device according to claim 19wherein said latch mechanism includes a pair of latch rods each having acam surface associated therewith and movable between first and secondrod positions that respectively correspond to the latch and unlatchstates, said lock mechanism including a cam element that interacts withthe cam surfaces such that rotation of said lock mechanism between thefirst and second rotational positions acts to cause movement of saidlatch rods between the first and second rod positions.
 21. A method ofsecuring a coupler section of a trailer that has a hitch ball recess,comprising: (A) engaging the hitch ball recess with a hitch ball elementthat is attached to a lock housing having at least one passageway and alock that is integral with the lock housing; (B) spanning a portion ofsaid coupler section adjacent to the hitch ball element with a firstportion of a shackle member in a manner such that said portion of saidcoupler section is positioned between said first portion of said shacklemember and said hitch ball element; (C) adjusting said first portion ofsaid shackle member to trap the portion of said coupler sectionnon-removably between said hitch ball element and said first portion ofsaid shackle member to define a locked state; and (D) lockably retaininga second portion of said shackle member relative to said hitch ballelement with said integral lock such that said first portion of saidshackle member is locked in the locked state.
 22. A method of securing acoupler section of a trailer according to claim 21 including the step ofselectively releasing said second portion of said shackle member suchthat said first portion of said shackle member is unlocked and removablethereby permitting disengagement with said portion of said couplersection.
 23. A method of securing a coupler section of a traileraccording to claim 21 wherein the step of adjusting said first portionof said shackle member is accomplished by a ratchet mechanism.
 24. Alocking device adapted to secure to a coupler section of a trailer,comprising: (A) a lock housing including a hitch ball element supportedthereby that is sized and adapted to mate with a coupler section of atrailer, said lock housing having a pair of spaced-apart passagewaysextending therethrough; (B) a shackle member releasably securable tosaid lock housing to define a retain state and releasable from said lockhousing to define a release state wherein said coupler section can beengaged by and released from said hitch ball element, said shacklemember including a pair of spaced-apart leg sections and a bridgesection extending therebetween, said leg sections respectivelyconfigured to pass through the pair of passageways when in the retainstate whereby said coupler section can be non-removably engaged betweensaid hitch ball element and said bridge section, at least one of saidleg sections has a latch structure thereon that is defined by aplurality of first latch teeth; (C) a latch mechanism disposed in saidlock housing and including at least one latch block having at least onesecond latch tooth that is operative to engage a selected one of saidfirst latch teeth when in the retain state to prevent removal of saidleg sections from said lock housing, said latch mechanism operative tomove between a latch state wherein said shackle member is latched in theretain state and an unlatch state wherein said shackle member may bemoved to the release state; and (D) a lock mechanism that is movablebetween a lock state to lock said latch mechanism in the latch statesuch that said shackle member is in the retain state and an unlock stateto unlock said latch mechanism so that it may move to the unlatch statethereby allowing said shackle member to move to the release state.
 25. Adevice for closing a socket of an unhitched trailer hitch coupler, saiddevice comprising: a locking bar wherein at least a portion thereofrests on top of the trailer hitch coupler; and a base comprising a plugmember for receipt within said trailer hitch coupler socket, a lockingbar-receiving aperture, and an integral lock for lockingly engaging saidlocking bar within said aperture.
 26. The device of claim 25 whereinsaid locking bar may be locked within said aperture at a plurality ofpositions therealong so that said device may accommodate trailer hitchcouplers of variable heights.
 27. A device for closing a socket of anunhitched trailer hitch coupler member, said device comprising: alocking bar having a pair of arms, wherein at least a portion of saidlocking bar rests on top of the trailer hitch coupler; a base comprisinga plug member for receipt within the trailer hitch coupler socket, apair of arm-receiving apertures, and an integral lock for lockinglyengaging a first said arm within a corresponding said arm-receivingaperture.
 28. The device of claim 27 wherein said first arm may belocked within said corresponding arm-receiving aperture at a pluralityof positions therealong so that said device may accommodate trailerhitches couplers of variable heights.
 29. The device of claim 27 whereinsaid locking bar comprises an inverted U-shaped member.
 30. A device forclosing a socket of an unhitched trailer hitch coupler member, saiddevice comprising: an inverted U-shaped locking bar having a pair ofarms, wherein at least a portion of said locking bar rests on top of thetrailer hitch coupler; a base comprising a pair of arm-receivingapertures located therein, a plug member for receipt within the trailerhitch socket located intermediate said apertures, and an integral lockfor lockingly engaging a first said arm within a corresponding saidarm-receiving aperture.
 31. The device of claim 30, wherein said firstarm may be locked within said corresponding arm-receiving aperture at aplurality of positions therealong so that said device may accommodatetrailer hitches couplers of variable heights.
 32. A method for closingthe a socket of an unhitched trailer hitch coupler member, said methodcomprising the steps of: providing a locking bar; providing a basecomprising a plug member, a locking bar-receiving aperture, and anintegral lock; inserting said plug member into the trailer hitch couplersocket; inserting a portion of said locking bar into said lockingbar-receiving aperture, wherein a least a portion of said locking barrests on top of said trailer hitch coupler; and locking said locking barwithin said locking bar-receiving aperture.
 33. A method for closing asocket of an unhitched trailer hitch coupler member, said methodcomprising the steps of: inserting a plug member into a trailer hitchcoupler socket, said plug member being attached to a base having a pairof arm receiving apertures extending therethrough and an integral lock;providing an inverted, U-shaped locking bar having a pair of arms;inserting said pair of arms into said pair of arm receiving apertures,wherein a portion of said locking bar rests on top of said trailer hitchcoupler; and locking at least one said arm within at least one saidaperture.